Attempt to define the mechanisms of adoptive immunotherapy used alone or in combination with chemotherapy in the treatment of tumors of C57BL/6, Balb/C, and (Balb/CXC57BL/6)F1 mice. Emphasis will be on: development of additional models of adoptive therapy of established tumors, using not only cells immunized in vivo, but also cells significantly sensitized to TAA primarily or secondarily in vitro; determination of the effector cell(s) responsible for tumor therapy by isolating, purifying, and characterizing subpopulations of immune cells using sera directed against B-cells and subsets of T-cells and with the use of a fluorescent activated cell sorter; characterization and purification of the cell subpopulations which suppress the therapeutic efficacy of the effector cells; determination of which sensitization regimens in vivo and in vitro facilitate the generation of cells which enhance or suppress the therapeutic effect.